# Unboundedness of Ball Multipliers and Bochner-Riesz

## Location

384H

Friday, December 2, 2022 1:00 PM

Yujie Wu

Besides the Kakeya needle problem, Besicovitch's sprouting of triangles has another interesting application. It gives a counterexample to the L^p multiplier problems, related to when should we expect a Fourier inversion property holds on R^n. We will describe this example and in case n=2 some basic results involving Bochner–Riesz Means. Reference: Grafakos, Modern Fourier Analysis, Third Ed, Sec 5.1, 5.2.